Per Unit Data of HTALP (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands		1 Months Ended	3 Months Ended								12 Months Ended
		Oct. 31, 2017	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Forward equity agreement, shares to be sold		2,600
Numerator:
Net income											$ 65,577	$ 47,345	$ 33,557
Net income attributable to noncontrolling interests	[1]										(1,661)	(1,433)	(626)
Net income attributable to common stockholders/unitholders											$ 63,916	$ 45,912	$ 32,931
Denominator:
Weighted average units outstanding - basic (in shares)											181,064	136,620	126,074
Dilutive effect of forward equity sales agreement (in shares)											17
Weighted average number of shares/units outstanding — diluted (in shares)											185,278	140,259	128,004
Earnings per common unit - basic:
Net income attributable to common stockholders/unitholders (in dollars per share)											$ 0.35	$ 0.34	$ 0.26
Earnings per common unit - diluted:
Net income attributable to common stockholders/unitholders (in dollars per share)											$ 0.34	$ 0.33	$ 0.26
Healthcare Trust of America Holdings, LP (HTALP)
Numerator:
Net income			$ 43,472	$ 13,957	$ (5,852)	$ 14,000	$ 17,154	$ 6,639	$ 13,516	$ 10,036	$ 65,577	$ 47,345	$ 33,557
Net income attributable to noncontrolling interests											(123)	(118)	(112)
Net income attributable to common stockholders/unitholders			$ 43,429	$ 13,929	$ (5,874)	$ 13,970	$ 17,064	$ 6,638	$ 13,520	$ 10,005	$ 65,454	$ 47,227	$ 33,445
Denominator:
Weighted average units outstanding - basic (in shares)											185,261	140,259	128,079
Dilutive units - partnership units convertible into common units (in shares)											0	0	0
Dilutive effect of forward equity sales agreement (in shares)											17	0	0
Weighted average number of shares/units outstanding — diluted (in shares)											185,278	140,259	128,079
Earnings per common unit - basic:
Net income attributable to common stockholders/unitholders (in dollars per share)			$ 0.21	$ 0.07	$ (0.03)	$ 0.10	$ 0.12	$ 0.05	$ 0.10	$ 0.08	$ 0.35	$ 0.34	$ 0.26
Earnings per common unit - diluted:
Net income attributable to common stockholders/unitholders (in dollars per share)			$ 0.21	$ 0.07	$ (0.03)	$ 0.10	$ 0.12	$ 0.05	$ 0.10	$ 0.08	$ 0.35	$ 0.34	$ 0.26

[1] Includes amounts attributable to redeemable noncontrolling interests.